The thyroid hormones are usually controlled by a feedback loop. The hypothalamus stimulates the production of TSH by the pituitary when there are low levels of thyroid hormone. TSH causes the thyroid gland to release the thyroid hormones T3 and T4 (Lee, 2013).
In hyperthyroidism, there is an overproduction of T3 and T4. Graves disease is the most common form of hyperthyroidism (Lewis, 2013).
In hyperthyroidism, there is an overproduction of T3 and T4. Graves disease is the most common form of hyperthyroidism (Lewis, 2013).